From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 69B51C07520 for ; Thu, 13 Sep 2018 13:37:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 240C420854 for ; Thu, 13 Sep 2018 13:37:03 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 240C420854 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729256AbeIMSqb (ORCPT ); Thu, 13 Sep 2018 14:46:31 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:59356 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728540AbeIMSqa (ORCPT ); Thu, 13 Sep 2018 14:46:30 -0400 Received: from localhost (ip-213-127-77-73.ip.prioritytelecom.net [213.127.77.73]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id 535EECF3; Thu, 13 Sep 2018 13:37:00 +0000 (UTC) From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Greg Edwards , Jens Axboe , Sasha Levin Subject: [PATCH 4.9 39/78] block: bvec_nr_vecs() returns value for wrong slab Date: Thu, 13 Sep 2018 15:31:26 +0200 Message-Id: <20180913131809.811762369@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20180913131805.732342940@linuxfoundation.org> References: <20180913131805.732342940@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Edwards [ Upstream commit d6c02a9beb67f13d5f14f23e72fa9981e8b84477 ] In commit ed996a52c868 ("block: simplify and cleanup bvec pool handling"), the value of the slab index is incremented by one in bvec_alloc() after the allocation is done to indicate an index value of 0 does not need to be later freed. bvec_nr_vecs() was not updated accordingly, and thus returns the wrong value. Decrement idx before performing the lookup. Fixes: ed996a52c868 ("block: simplify and cleanup bvec pool handling") Signed-off-by: Greg Edwards Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- block/bio.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/block/bio.c +++ b/block/bio.c @@ -155,7 +155,7 @@ out: unsigned int bvec_nr_vecs(unsigned short idx) { - return bvec_slabs[idx].nr_vecs; + return bvec_slabs[--idx].nr_vecs; } void bvec_free(mempool_t *pool, struct bio_vec *bv, unsigned int idx)